Compensating bearing

ABSTRACT

A bridge bearing in which a substructure and a superstructure are displaceably connected to each other by means of a sliding bearing, whereby the displacement occurs in a linear and/or cardanic manner in at least one of the directions X, Y, and Z. The bearing is characterized in that a carriage ( 7 ) that is connected to a cover plate ( 10 ) is guided in a linear manner in the X and/or Y direction by two interspaced shafts ( 5, 4 ), respectively, on which displaceable slide bushings ( 9, 8 ) are arranged and/or the cover plate can be guided in a tiltable manner by a pivot bearing ( 18 ) in the Z direction. This combination of a linear and pivot bearing enables all alignment errors arising as a result of finishing inaccuracies, foundation subsidence, desired and undesirable slanting to be compensated and regulates the variations in lengths due to temperature and load.

AREA OF THE INVENTION

The invention relates to a compensating bearing, for example, a bridgebearing or a travel way bearing, in which a substructure and asuperstructure are displaceably connected to each other by means of asliding bearing, whereby the displacement occurs in a linear and/orcardanic manner in at least one of the directions X, Y, and Z in ahypothetical three-dimensional coordinate system.

BACKGROUND

Compensating bearings of this type, which for their part rest onabutments or piers, transfer the load from the superstructure to thesubstructure, whereby the superstructure moves in the longitudinaland/or transverse direction. In order to receive twisting angles,bearings of this type must, however, also be combined with a pivotingpart.

A bridge bearing of this type according to the generic concept is knownfrom the pamphlet “Innovation in Steel”, No. AG 01 D-3000-12.97 of theMaurer Söhne Company. It consists of a base plate, on which anintermediate plate that can be moved in the X-direction is arranged,which in turn carries a second intermediate plate that can be moved inthe Y direction. This second intermediate plate has a curved recess, inwhich a complementary spherical section is placed. This bridge bearingaccording to the generic concept is then closed by a cover plate, whichcan perform linear movements in the direction of the two axes X, and Y,and can pivot around the Z axis.

A bridge bearing of this type has, on the one hand, relatively largedimensions and on the other hand, is relatively imprecise in itsadjustability with regard to the X, Y, and Z axes. An additionaldisadvantage is in its insufficient freedom of play.

SUMMARY

The objective of the invention is thus to develop an improvedcompensating bearing while avoiding the previous disadvantages.

According to the invention, this objective is achieved by providing acarriage that is connected to a cover plate that is guided linearly inthe X- and/or Y-direction respectively via two shafts that are set apartat distances from each other, on which slide bushings that can be movedare arranged and/or that the cover plate is guided so that it can betilted in the Z-direction via a first pivot bearing.

The decisive advantage of this bearing is its clear differentiation withregard to the function of the three movement axes. The slide bushingsensure an absolute maintenance freedom at the lowest level of friction.Bearing elements that are adjusted to the load, such as slide bearingsand pivot bearings, reduce the total weight of the bearing constructionand require little construction space. The round and/or sphericalbearing elements are self-centering, which makes possible a highprecision and a good side stability. The combination according to theinvention, made of linear bearings and plain bearings, enables allalignment errors arising as a result of finishing inaccuracies,foundation subsidence, desired and undesirable slanting to becompensated and regulates the variations in lengths due to temperatureand load by having a good damping capacity.

An especially advantageous compensation bearing, which makes possiblethe reception of forces from all three movement directions, is alsoprovided. This X-, Y-, and Z-bearing is characterized in that a baseplate has four projecting shaft holders that are set apart from eachother in the X-direction and in the Y-direction, and in which twoY-shafts are held, on each of the Y-shafts, an additional shaft holderis arranged so that it can be moved, which are connected to each otherby two X-shafts, so that the carriage guided on the X and Y shafts viathe sliding bushings can be moved linearly in both directions, and thatthe carriage has a curved shaft disc that is received in an associatedrecess of the cover plate so that the cover plate can be tilted in theZ-direction.

According to another characteristic of the invention, it is providedthat the slide bushings are maintenance-free cylindrical slide bushingsbased on PTFE.

These dry slide bearings that are known to persons skilled in the artinclude cylindrical steel supporting structures and the maintenance-freeslide layer. The steel structure protects against damages in thehandling and during installation. The slide layer is generally formed ofa 0.5 mm strong PTFE fabric, generally embedded in artificial resin andaffixed in a high-strength manner to the support structure. The flowbehavior of the slide layer is almost negligible in the connection withthe support structure even for high loads. The adhesive connection ismoisture-stable and does not swell.

In another aspect, it is apparent that the Y-shafts are affixed in theshaft holders using mounting caps, which are pressed from the outsideagainst the shaft holder with a mounting bolt that is arranged in thefacing ends of the Y-shafts. In this way, a simple and secure attachmentof the Y-shafts results.

According to an additional characteristic of the invention, it isprovided that the X-shafts each have a curved recess on the oppositeends, into which the Y-shafts are inserted with a part of theircircumferential surface. This has the advantage that by the recess, thebearing attachment of the X-shafts is done in an elegant manner throughthe Y-shafts.

An especially advantageous form of the bearing according to theinvention, provides that the base plate has in its middle part asupporting projection that projects in the direction of the cover plateand is contacted by the lower side of the carriage in the unloadedcondition.

This has the advantage that the introduction of force on the bearingdoes not occur via the X- and the Y-shafts, but directly on the baseplate, so that an entirely especially stable embodiment of the bearingresults.

In another aspect, the X and/or Y shafts should have a deflection in thedirection of the cover plate. This makes it so that shafts equipped inthis manner have a certain spring action so that the bearing ispretensioned.

An additional, especially advantageous embodiment of the invention,provides that the carriage include in its middle part a hole goingthrough that is provided with a shoulder. A second pivot bearing is setinto the hole and is held via a mounting bolt that is inserted into thecover plate, whereby in the area of a journal of the carriage, a gap isformed between the mounting bolt and the through-hole. In this processit is advantageous that upon a change of the forces into the negativerange, the Z-axis can not lift off of the cover plate, i.e. a securingagainst lift-off is formed. In this case, it is necessary that bothpivot bearings have a common spherical center.

In another aspect, the pivot bearings can be constructed asmaintenance-free axial plain bearings, radial plain bearings, orinclined plain bearings based on PTFE. These pivot bearings arepre-assembled units, which include shaft discs and housing discs andmaintenance-free slide layers in the housing discs. The shaft disc has aspherical outer sliding path, while the housing disc is provided with ahollow-spherical inner sliding path and with an adhered slide layer.Pivot bearings of this type are then used if, for example, high loadsare transferred with slight movements.

An additional advantageous embodiment form of an X-Z-bearing isdescribed, in which a base plate has two projecting shaft holders thatare set apart from each other in the X-direction in which two X-shaftsset apart from each other are held. Slide bushings that can be moved ina linear direction that are connected with the carriage are arranged onthe X-shafts, and the carriage has a curved shaft disc that is receivedin a corresponding recess of the cover plate so that it can be tilted inthe Z-direction.

The associated opposing piece, namely a Y- Z-bearing, is also providedin which a base plate should have two projecting shaft holders that areset apart from each other in the Y-direction in which two Y-shafts thatare set apart from each other are held, on which slide bushings arearranged on the two Y-shafts that can be moved in a linear direction andare connected with the carriage, and the carriage, has a curved shaftdisc that is received in a corresponding recess of the cover plate sothat it can be tilted in the Z-direction.

Finally, a Z-bearing is described, i.e. a bearing with only one degreeof freedom. Bearings of this type are used especially as so-called fixedbearings. It is characterized in that the base plate is provided with aprojection that projects in the direction of the cover plate, which isprovided on its upper end with a circular-ring shaped curved shaft disc,which is included in a corresponding recess of the cover plate so thatit can be tilted in the Z-direction.

BRIEF DESCRIPTION OF THE DRAWING(S)

The invention is explained in greater detail on the basis of thepreferred embodiment in connection with the attached drawings.

Shown are:

FIG. 1 is a perspective view of an X-, Y-, and Z-bearing according tothe invention,

FIG. 2 is a front view of this bearing,

FIG. 3 is a side view of this bearing, in partial section,

FIG. 4 is a section view along the line A—A in FIG. 3,

FIG. 5 is a section view along line B—B in FIG. 3,

FIG. 6 is a perspective view of an X-, Z-bearing according to theinvention,

FIG. 7 is a perspective view of a Y-, Z-bearing according to theinvention,

FIG. 8 is a perspective view of a Z-bearing according to the invention,

FIG. 9 is a side view of the bearing according to FIG. 8,

FIG. 10 is a section along the line A—A in FIG. 9,

FIGS. 11-15 are sequential perspective views of an X-, Y-, Z-bearingaccording to the invention during different stages of construction.

FIG. 16 is a side view similar to FIG. 3, in which the X-shafts have adeflection in the direction of the cover plate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to FIGS. 1 to 5 the X-, Y-, Z-bearing indicated with 1according to the invention is shown and includes a base plate 2 providedwith mounting bore holes 21, on which four shaft holders 3 projecting inthe X and Y direction and set apart from each other, are arranged. Inthese paired shaft holders 3, two Y-shafts 4 are housed, the mounting ofwhich is done by mounting caps 11, which are pressed from the outsideagainst the shaft holders 3 via the mounting bolts 12 that are screwedinto the Y-shafts 4. In the Y-direction, between each pair of shaftholders 3, an additional shaft holder 6 is arranged, whereby both shaftholders 6 are connected to each other by two X-shafts 5 which are spacedapart from each other. The intersection of both shafts 4, 5 is madepossible by an opposing recess of the X-shaft, as shown in FIG. 4. Onthe X-shafts 5, a carriage 7 is guided on slide bushings 9. The carriage7 is connected to a cover plate 10 provided with longitudinal bore holes22. This carriage 7 can be moved in the X-direction by the amount “a”from a neutral position both to the right and to the left, as shown inFIG. 3. The X-shafts 5 in turn can also be moved in the Y-direction, asshown in FIG. 4, by the amount “b” from a neutral position both to theright and to the left. The movement in the Y-direction is done by usingthe shaft holder 6 and its slide bushings 8.

As can be ascertained from FIG. 5, the carriage 7 is equipped in itsmiddle part with a through hole 14. On a shoulder 31 of the through hole14, a pivot bearing 15 rests, which is held with a mounting bolt 17 thatis screwed into the through-hole 16 of the cover plate 10. A journal 23of the carriage 7 is surrounded by a shaft disc 19 of a pivot bearing18, whereby the shaft disc 19 can be accommodated by a recess 20 in thecover plate 10. In this way, a securement against lift-off is formed,which prevents a lift-off of the cover plate 10 from the carriage 7. Apivoting of the cover plate 10 is only possible in the existing lift-offprotection to the extent that the air gap 30, shown in FIG. 5, isprovided between the shaft of the mounting bolt 17 and the through-hole14 allows in the area of the journal 23 of the carriage 7.

As shown further in FIG. 1 and FIG. 5, the base plate 2 is provided witha carrying projection 13 that points in the direction of the cover plate10, so that between the carriage 7 and the carrying projection 13, thereis no gap, i.e. the introduction of forces is done directly on the baseplate 2. In this case, it is advantageous to provide the underside ofthe carriage 7 with a corresponding sliding layer.

If the carrying projection 13 is missing, then a gap is formed betweenthe base plate 2 and the carriage 7, so that introduction of forces isdone on the base plate 2 via the X-shafts 5 and the Y-shafts 4.

The X-, Z-bearing shown in perspective in FIG. 6 can, as alreadyexpressed by its name, be moved linearly in the direction of the X-axisand can be tilted around the Z-axis. As a result, the Y-shafts 4 areunnecessary, as opposed to the X-, Y-, Z-bearing described above.Otherwise, the bearing structure is mainly the same. This bearing has,furthermore, no mounting securing mechanism, so that the pivot bearing15 can be omitted.

In FIG. 7, a Y-, Z-bearing is also shown in a perspective form. Thedesign is similar to the X-, Y-, Z-bearing described in FIGS. 1 to 5,whereby because of the two degrees of freedom, the X-shafts 5 can beomitted.

Finally, in the FIGS. 8, 9, and 10, a Z-bearing is shown, which can beswiveled around the Z-axis and inserted as a fixed bearing. As can beseen from the Figures, the base plate 2 is provided with a projection 27that points in the direction of the cover plate 10, which has on itsupper end a shaft disc 19 of a pivot bearing 18. The cover plate 10 inturn is equipped with an opposing projection 28, which is equipped witha ball-shaped recess 20, so that in turn a pivot bearing 18 is formed.This Z-bearing is already equipped in such a way with a mechanism tosecure against lift-off in the manner described whereby the projection27 is provided with a hole 14 that goes through it, which has a shoulderthat is not described in greater detail. On this shoulder, a pivotbearing 15 rests, which in turn is held with a mounting bolt 17. Usingthis mounting bolt 17, the pretensioning of the bearing can be produced.

In FIGS. 11 to 15, an X-, Y-, Z-bearing is shown in perspective in thestages of construction. As can be recognized in FIG. 11, the base plate2 is provided with mounting holes 21, which function for mounting of aconnecting construction. Shaft holders 3 provided with through-holesextend from of the base plate 2. In the middle part of the base plate 2,the carrying projection 13 is visible. As can be recognized from FIG.12, Y-shafts 4 are received in the reception holes of the shaft holder3. On these Y-shafts 4, the two slide bushings 8 are arranged. Under theY-shafts 4 lie two X-shafts 5, which are provided in the area of theslide bushings 8 with a arc-shaped recess, so that the Y-shafts 4 and/orslide bushings 8 partially extends in this recess. In this way, amovement of the X-shafts 5 is prevented. Lying between the X-shafts 5,the pivot bearing 15 with the mounting bolt 17 is indicated.

According to FIG. 13, a completion of the X-, Y-, Z-bearing is done insuch a way that the X-shafts 5 that carry the shaft holder 6 are shown.On these X-shafts 5, the carriage 7 is shown movably mounted, whichcarries in its inside the pivot bearing 15 (not shown), whereby thecarriage 7 is provided with the journal 23. Also to be recognized is themounting bolt 17, which is screwed into the cover plate 10 not shownhere. As can be recognized from FIG. 14, the bearing is now completed insuch a way that a shaft disc 19 of the pivot bearing is placed aroundthe journal 23 of the carriage 7. Finally, in FIG. 15, the bearingcompleted with the cover plate 10 is shown. It has in its center thethrough-passage hole 16, in which the mounting bolt 17 is screwed in.

As shown in FIG. 16, the X-shafts 5′ can have a deflection in thedirection of the cover plate 10, if desired. It is also possible for theY-shafts to be deflected toward the cover plate 10 in a similar manner.

1 X-, Y-, Z-bearing 2 Base plate 3 Shaft holder for Y-shaft 4 Y-shaft 5X-shaft 6 Shaft holder for X-shaft 7 Carriage 8 Slide bushing on theY-shaft 9 Slide bushing on the X-shaft 10 Cover plate 11 Mounting cap 12Mounting bolt 13 Carrying projection 14 Through hole 15 Second pivotbearing 16 Through hole 17 Mounting bolt 18 First pivot bearing 19 Shaftdisc 20 Recess 21 Mounting bolt 22 Longitudinal bore hole 23 Journal 24X-, Z-bearing 25 Y-, Z-bearing 26 Z-bearing 27 Projection 28 Opposingprojection a Movement amount in the X- direction b Movement amount inthe Y- direction

What is claimed is:
 1. A bridge bearing adapted to slideably connect asubstructure and a superstructure to each other, whereby displacementoccurs in a linear and/or cardanic manner in at least one of horizontalX and Y directions and tiltable in a Z direction in a hypotheticalthree-dimensional coordinate system, the bearing is constructed as anX-, Y-, and Z-bearing comprising a base plate (2) that has fourprojecting shaft holders (3) that are set apart from each other in whichtwo Y-shafts (4) are held, whereby on each of the Y-shafts (4) anadditional shaft holder (6) is movably arranged, the additional shaftholders are connected to each other by two X-shafts (5), and a carriage(7) is guided on the X and Y shafts (5, 6) by slide bushings (9, 8) andcan be moved linearly in both the X and Y directions, and the carriage(7) has a curved shaft disc (19) thereon that is received in acomplementary recess (20) of a cover plate (10) connected to thecarriage so that the cover plate (10) can be tilted in the Z-directionby a first pivot bearing (18) formed by the shaft disc containing thecover plate wherein the Y-shafts (4) are affixed in the projecting shaftholders (3) using mounting caps (11), each of which are pressed againstthe respective projecting shaft holder (3) with a mounting bolt (12)that is located in facing ends of the Y-shafts (4).
 2. The bridgebearing according to claim 1, characterized in that the slide bushings(8, 9) are maintenance-free cylindrical slide bushings formed of Teflon.3. The bridge bearing according to claim 1, characterized in that theX-shafts (5) each have a curved recess on opposite ends thereof, intowhich the Y-shafts (4) are set.
 4. The bridge bearing according to claim1, characterized in that the base plate (2) has in a middle part thereofa supporting projection (13) that projects in a direction of the coverplate (10) and is contacted by a lower side of the carriage (7) in anunloaded condition.
 5. The bridge bearing according to claim 1,characterized in that the X and/or Y shafts (5, 4) have a deflection ina direction of the cover plate (10).
 6. The bridge bearing according toclaim 1, characterized in that the carriage (7) has in a middle partthereof a hole (14) extending therethrough that is provided with ashoulder, into which a second pivot bearing (15) is set and is held viaa mounting bolt (17) that is inserted into the cover plate (10), wherebyin an area of a journal (23) of the carriage (7), a gap is formedbetween the mounting bolt (17) and the hole (14).
 7. The bridge bearingaccording to claim 6, characterized in that the first and the secondpivot bearings (18, 15) have a common spherical center.
 8. The bridgebearing according to claim 6, characterized in that first and the secondpivot bearings (18, 15) are constructed as maintenance-free axial pivotbearings, radial pivot bearings, or inclined pivot bearings formed ofTeflon.